A mesa is an isolated, flat-topped elevation, ridge or hill, which is bounded from all sides by steep escarpments and stands distinctly above a surrounding plain. Mesas characteristically consist of flat-lying soft sedimentary rocks capped by a more resistant layer or layers of harder rock, e.g. shales overlain by sandstones. The resistant layer acts as a caprock that forms the flat summit of a mesa. The caprock can consist of either sedimentary rocks such as sandstone and limestone; dissected lava flows; or a deeply eroded duricrust. Unlike plateau, whose usage does not imply horizontal layers of bedrock, e.g. Tibetan Plateau, the term mesa applies exclusively to the landforms built of flat-lying strata. Instead, flat-topped plateaus are specifically known as tablelands.
Zhangdian District, Zibo Municipal District, Shandong Province, is located in the middle of Zibo City; the terrain slows down gradually from south to north, and belongs to the warm temperate monsoon semi-dry and semi-humid continental climate zone; it has jurisdiction over 6 towns and 7 streets, with a total area of 244 square kilometers; the total population in 2017 is 687121. Zhangdian District is the transportation and communication hub in central Shandong and one of the important node cities in Jinan metropolitan area. It is 70 kilometers away from Jinan International Airport, 210 kilometers away from Qingdao Port and 380 kilometers away from Yantai Port. Jiaoqing Expressway and Binlai Expressway meet here. Jiaoji Railway and 309 National Highway run from east to west, National Highway 205 runs from north to south, and 16 trunk highways lead to the whole country. After the completion of the north line of the Ji-Qing high-speed railway, it will reach Jinan in 20 minutes, Qingdao in 1 hour and Beijing in 2 hours. 2017